6.2L (L9H) Owners - Get all your questions answered here

[NemesisC5]

Don't get your nylons in a knot - I misunderstood your question! GEESH ....

 

 

BUT .. headers are inherently going to make the vehicle louder, so ....

 

I'm familiar with headers on many applications and in general I like the throaty visceral exhaust note they make.

 

It's the L9H with VVT that was said to make more "mechanical noises" that I am concerned with.

 

Typical stock manifolds help isolate these sounds on any vehicle and headers make these sounds more noticeable on any vehicle.

 

With the added complexity of VVT it seems plausible that extra valvetrain noise could be present and made more noticeable with long tube headers.

 

I'm asking if anyone that owns an L9H with long tube headers can tell me if there truck has more mechanical noise than a non VVT truck?

[401 YJ]

I just intalled my headers last night and as far as mechanical noise I don't really notice anything more then the normal header noise. It almost sounds like an axhaust leak but it is not. I want to describe it as a tinny sound. Not very noticeable unless you know that truck very well. I had a set of LT Headers on a half ton silverado with the throttle body 350 and the mechanical sound or header tick is no different on this truck then the old 350.

 

I have a corsa system with ARH LT headers and no Cats. At highway speeds of 60 to 70 in the cab there is no noticeable difference in sound level. The second you give any throttle it is loud. I thought I had a window open in the back of the truck it was so loud. It is very controllable though. It sounds just slightly louder then stock at idle or easlily driving around town but will wake the enitre neighborhood up if you really lay into it.

 

I have had the Corsa system for a while now with the stock manifolds and cats and was very dissapointed in the sound level. The system was very high quality and installed supe easy, but the stock exhaust system was louder. At wide open throttle it had a little more noise level but not enough for me. I no longer have that problem.

 

The headers went on very smoothly and fit perfectly. No fitment issues at all. If anyone else is doing this, remove the passenger side inner fenderwell and your life will be much easier. Driver side there is no need to remove. I had to cut the old "Y" pipe out. I just could not see anyway to get it out without removing the cross member.

[NemesisC5]

I just intalled my headers last night and as far as mechanical noise I don't really notice anything more then the normal header noise. It almost sounds like an axhaust leak but it is not. I want to describe it as a tinny sound. Not very noticeable unless you know that truck very well. I had a set of LT Headers on a half ton silverado with the throttle body 350 and the mechanical sound or header tick is no different on this truck then the old 350.

 

I have a corsa system with ARH LT headers and no Cats. At highway speeds of 60 to 70 in the cab there is no noticeable difference in sound level. The second you give any throttle it is loud. I thought I had a window open in the back of the truck it was so loud. It is very controllable though. It sounds just slightly louder then stock at idle or easlily driving around town but will wake the enitre neighborhood up if you really lay into it.

 

I have had the Corsa system for a while now with the stock manifolds and cats and was very dissapointed in the sound level. The system was very high quality and installed supe easy, but the stock exhaust system was louder. At wide open throttle it had a little more noise level but not enough for me. I no longer have that problem.

 

The headers went on very smoothly and fit perfectly. No fitment issues at all. If anyone else is doing this, remove the passenger side inner fenderwell and your life will be much easier. Driver side there is no need to remove. I had to cut the old "Y" pipe out. I just could not see anyway to get it out without removing the cross member.

Thanks for the summary and opinion. Did you tune after install? Can you feel the power gain from the install?

[RyanbabZ71]

I bet so. The increase is very noticeable in my car it's great

 

 

Ryan

[401 YJ]

I just put a Black Bear tune in my truck a few weeks ago and that made a very noticeable difference. With the headers there is a very noticeable difference in how quick the motor revs. The truck feels like it has a lot more low end torque. It doesn't shift out of 6th nearly as often as it did before. I have only put about 100 miles on it so far.

 

I will be getting an updated tune from Black Bear soon to account for the headers and no Cats. Oddly I don't have any check engine lights on yet. I have to assume I will. Does it take time for the computer to figure out what is going on.

 

I will post once I get the updated tune installed. My dad has almost the same truck I do with a 6.2 but it is an extended cab. I am looking forward to doing a side by side comparison. His truck is totally stock. Mine has a 2" leveling kit and 285 tires. I am hoping to see a big difference between the two trucks.

[RyanbabZ71]

It took mine a few days to get a CeL

 

 

Ryan

[SierraRx6.2]

I have a question regarding the stock exhaust on my 2010 GMC Sierra 6.2L. When I drive up an incline and under acceleration I have this whistling/whining noise that happens every so often and didn't know if this was something normal or if I need to look into getting something replaced. Stock exhaust sounds great and there isn't much I would change, but have been looking at some of the forums and debating between the Corsa and the Borla if this could be something needing repair or replacing.

[mymaggiebell]

I have a question regarding the stock exhaust on my 2010 GMC Sierra 6.2L. When I drive up an incline and under acceleration I have this whistling/whining noise that happens every so often and didn't know if this was something normal or if I need to look into getting something replaced. Stock exhaust sounds great and there isn't much I would change, but have been looking at some of the forums and debating between the Corsa and the Borla if this could be something needing repair or replacing.

i have the borla dual exhaust and i have always gotten compliments. a little bit of buyers remorse as i do like the sound of the corsa systems. my friend has an escalade and he put in a flow master and a borla tip. that sounds pretty nice too. there is a lot of excess weight and it is cleaner with aftermarkets. just to note my exhaust is quiet to me when i am driving, yet my wife gives me shit as she says she can hear me a mile away!

[401 YJ]

Just an update on my Header install. I have put about 1000 miles on it so far with the AR LT Headers and updated Black Bear Tune. I also just got back from a trip towing my Jeep and 2 atv's on my car trailer. Total weight of truck and trailer was just under 14,000lbs. Truck can hold 6th gear way better and pulls much, much better. I also averaged just a little over 10 miles to the gallon. I pulled the same load to Colorado and back in August before I made any modifcations and averaged just under 9 mpg. My truck does not have the Max Tow option so I only have 3.42 gears.

 

The only problem I have now is the trucks rear springs are not heavy enough to handle the weight. I am almost on the bump stops when I get teh load where I need it for the truck to handle correct. Has any one installed helper airbags to help with this problem?

[Jsdirt]

Airbags are where it's at - you will love them. I've got the Firestone RideRite 2430. My springs would sag with just me standing on the tailgate, and now I can throw a 2,400 lb. pallet of coal in the back and keep the truck dead level.

 

Normal driving I only keep 4-5 psi in them. With my weight distribution hitch for my flatbed car hauler, I normally never change that setting. I think a weight distributing hitch would be a better way to go, especially if you tow a lot. It changes the handling unbelievably, and it will level the truck out as well. Towing feels like your driving a straight job. Feels like the trailer is welded to your truck's frame.

Edited September 23, 2015 by Jsdirt

[401 YJ]

 

I don't mind the way it handles the load I just really hate how it looks and all the headlights flashing me when I meet cars at night.

[Buddy67Lincoln]

Need advice : my 2010 Yukon has the 6.2 and it has sticky lifters. Is this issue typically specific lifters or any of them could go bad? Got the dealer to flip the bill to go in and fix the bad ones but they offered to put in new lifters at cost of parts for the ones that are not bad as preventative maintenance. They said the parts numbers are different so I hope it's an improved and fixed replacement. Just not sure if I should bite on $4-500 out of my pocket for finishing off the lifters the aren't sticking. Thanks for any help.

[Jsdirt]

I bet neither Lincoln you own ever had this problem! Total joke manufacturing is these days. It's not enough to spend $40 LARGE on a truck - they have to throw sh** parts in it that fail 5 years (or less) in. What a world ...

 

If it were me, I would leave the thing alone, and drive it until it grenades - then, I'd throw in a long block built by a reputable engine builder. That engine will last just about forever. I wouldn't spend one more dime at GM for the same crap quality parts.

 

Just my humble .02 ....

[Buddy67Lincoln]

Yeah I'm on the fence over this. They found 3 bulletins on this issue. Tearing down the engine to do this is nuts on a $60,000 SUV new. Granted I didn't buy it new but I'm still surprised to see such a "reliable" engine have this issue. And it's very common. Surprised GM is still selling trucks with these engines. Wait; now they are EcoTechs! Vortec is dead so now everything must be all better.

[Jsdirt]

That's what infuriates me about GM. The engine by itself is bulletproof, and the block & lower end is stronger than the old 350's of the day, but then they go and throw substandard lifters in ... and top it off with hit-or-miss crap electronics. Can't win today ....

 

I love my engine by itself. Thing makes a ton of power and gets the same mileage as my '94 did -pretty impressive. But then they throw in an unreliable AFM that makes it burn oil. NONE of my cars or trucks in the past have EVER burned oil, even with close to 300k on the clock. Mine started burning at 50k ...

 

My parent's could have bought 3 of their houses for what the average SUV sells for today too. For that kind of money, these things should have the reliability of military aircraft. God knows GM didn't pay $50k a piece to build these things ...